A computer system may include one or more central processing units (CPUs) or processor(s). The CPU(s) may be coupled to a chip set (for example, via a bus). The chipset may include a memory controller hub (MCH) including a memory controller coupled to a system memory. The system memory stores data and responds to the memory controller through a sequence of instructions that are executed by the CPU(s) or processing device(s) included in the computing system. The MCH may also include, for example, a display controller coupled to a display. The chipset further may include an input/output control hub (ICH) coupled, for example, to the MCH via a hub interface. The ICH may be coupled, for example, to one or more input/output (I/O) devices. The ICH may also be coupled to a peripheral bus (for example, a Peripheral Component Interconnect or PCI bus). A PCI bridge may be coupled to the PCI bus to provide a data path between the CPU(s) and peripheral devices.
The system memory controlled by the memory controller may be a dynamic memory (for example, a Dynamic Random Access Memory or DRAM), a memory module, a dual in-line memory module (DIMM), a fully buffered dual in-line memory module (FB-DIMM), a Double Date Rate 2 (DDR2) memory, and/or a Double Data Rate 3 (DDR3) memory, for example. A Fully Buffered Dual Inline Memory Module (FB-DIMM) includes an onboard Advanced Memory Buffer (AMB) to support a serialized memory subsystem architecture. FB-DIMMs may be used, for example, to reduce the collective DRAM capacitive loading effects and to increase system memory by allowing more DIMMs (using more memory sockets) in a system. FB-DIMMs do not typically increase the speed of the memory subsystem, but they do increase the memory density (and capacity). The Advanced Memory Buffer (AMB) is often an integrated circuit (or chip) that is the memory module's interface between the memory controller (for example, of the motherboard and/or of the MCH) and all the other FB-DIMM modules on the motherboard. An AMB is a component within the memory that allows buffering of memory traffic to support large memory capacities. The AMB interface handles FB-DIMM channel and memory requests to and from the local DIMM, and forwards requests to other DIMMs on the FB-DIMM channel. At higher speeds, serial channel input/output (I/O) drivers require high power for driving the bit lanes across the memory DIMM, socket, and part of the next DIMM. Therefore, a lower power and/or higher capacity solution would be advantageous.